WUSTOJ 1325: Distance（Java）坐标计算
题目链接：1325: Distance
Description
There is a battle field. It is a square with the side length 100 miles, and unfortunately we have two comrades who get hurt still in the battle field. They are in different positions. You have to save them. Now I give you the positions of them, and you should choose a straight way and drive a car to get them. Of course you should cross the battle field, since it is dangerous, you want to leave it as quickly as you can!
有一个战场。这是一个边长100英里的正方形，不幸的是我们还有两个同志在战场上受伤。他们处于不同的位置。你必须拯救他们。现在我给你它们的位置，你应该选择一条直线，然后开车去取它们。当然你应该穿过战场，因为它很危险，你想尽快离开它!
Input
There are many test cases. Each test case contains four floating number, indicating the two comrades’ positions (x1,y1), (x2,y2).
Proceed to the end of file.
有许多测试用例。每个测试用例包含四个浮点数，表示两个同志的位置 (x1, y1)， (x2, y2) 。
继续到文件末尾。
Output
you should output the mileage which you drive in the battle field. The result should be accurate up to 2 decimals.
你应该输出你在战场上行驶的里程。结果应该精确到小数点后两位。
Sample Input
1.0 2.0 3.0 4.0
15.0 23.0 46.5 7.0
0.0 0.0 100.0 0.0
100.0 0.0 100.0 100.0
0.0 0.0 100.0 100.0
0.0 100.0 100.0 0.0
20.0 5.0 40.0 20.0
30.0 30.0 80.0 90.0
20.0 12.0 40.0 34.0
30.0 80.0 70.0 20.0
40.0 70.0 80.0 30.0
40.0 75.0 60.0 50.0
20.0 15.0 40.0 10.0
20.0 70.0 50.0 85.0
10.0 44.0 30.0 52.0
Sample Output
140.01
67.61
100.00
100.00
141.42
141.42
108.33
130.17
135.15
120.19
127.28
128.06
82.46
89.44
107.70
HINT
The battle field is a square local at (0,0),(0, 100),(100,0),(100,100).
战场是一个位于 (0, 0)，(0, 100)，(100, 0)，(100, 100) 的正方形。